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Tyddyn Castle Mound is a medieval motte built upon bedrock of the South Wales Middle Coal Measures Formation. The underlying mudstone, siltstone and sandstone, deposited during the Moscovian period of the Carboniferous, provided a stable foundation for the earthwork's construction. This geological setting, typical of the South Wales coalfield region, would have offered relatively firm ground for the mound's ditch and rampart.
The motte represents a form of fortification common throughout medieval Wales and the Welsh Borders, comprising an artificial or enlarged mound topped by a timber palisade and keep. Such structures served as administrative centres and defensive strongholds during the period of Anglo-Norman expansion into Wales, typically dating from the 11th to 13th centuries.
The monument is recorded and protected by Cadw, the Welsh heritage agency, under reference FL126. This designation ensures the preservation of this important earthwork as evidence of medieval settlement and military organisation within Wales. Its survival as an upstanding feature allows the mound's form and proportions to remain visible in the modern landscape, retaining archaeological potential for future study.
Tyddyn Castle Mound is a scheduled monument protected by Cadw under reference FL126. View the official record →
Tyddyn Castle Mound is a medieval motte built upon bedrock of the South Wales Middle Coal Measures Formation. It is designated a Scheduled Ancient Monument by Cadw under reference FL126.
Tyddyn Castle Mound dates from the medieval period, and is classified as a motte. It is one of over 32,000 scheduled monuments protected across the UK.
Tyddyn Castle Mound is a Scheduled Ancient Monument, legally protected by Cadw — the body responsible for designating and safeguarding heritage sites in Wales. The official designation reference is FL126.
Several scheduled monuments lie within 10 km, including Offa's Dyke: Section extending 117m NW of Church (7.1 km), Bridge 157m E of Ffrith Village (8.6 km), Ffrith Roman Site (8.7 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Tyddyn Castle Mound's history, each drawn from the record and mapped to the exact spot:
Every location is different. Not every section appears for every place, only what the historical record actually holds turns up in a report.
Tyddyn Castle Mound stands on Pennine Middle Coal Measures Formation And South Wales Middle Coal Measures Formation (Undifferentiated), bedrock that formed in the Moscovian. The rock here is mudstone, siltstone, sandstone, coal, ironstone and ferricrete.